cod does have scenario in all of series...its the battlefield who started lore with bad company-2 and bf3Because World of Warcraft is at its a core, a game.
Sure as a game, it puts much more weight on lore, and that lore is usually what drives the game in the first place, but what most people have to recognize is that World of Warcraft is fundamentally a game.
All the best lore in the world won't compensate for the fact that your game sucks.
CoD is a good example of a game with no lore that succeeds. World of Warcraft simply incorporates more lore into their gaming experience.
Also, regarding not having lore events, time and resources are vital. Game developers have to decide whether to implement events that have lore or not, so the dimension of acceptability and feasibility is introduced. Sure having more events is nice, but it has to meet the bottom line of whether it enhances the gaming experience or not.
Lore compliments the game; not the other way around. Lore serves the game; not the other way around.